import time
import math
from machine import ADC, Pin
global NTC_pin
last_button_time_stamp = 0

BETA = 3950  
R1 = 10000  
V_REF = 3.3  

NTC_pin = machine.ADC(26)
NTC_ADC = 0
button_pressed = False
def int_handler(pin):
    global button_pressed

    global last_button_time_stamp

    cur_button_ts = time.ticks_ms()
    button_press_delta = cur_button_ts - last_button_time_stamp
    if button_press_delta > 200:
        last_button_time_stamp = cur_button_ts
        button_pressed = True
    

def temp():
    NTC_ADC = NTC_pin.read_u16()
    voltage = (NTC_ADC / 65535) * V_REF
    resistance = R1 / ((V_REF / voltage) - 1)

    kelvin = 1 / (1 / 298.15 + 1 / BETA * math.log(resistance / 10000))
    celsius = kelvin - 273.15
    return celsius

def main():
    global button_pressed
    button = Pin(0, Pin.IN, Pin.PULL_UP)
    button.irq(trigger = Pin.IRQ_FALLING, handler = int_handler)
    while True:
        if button_pressed == True:
            button_pressed = False
            x = temp()
            print(x)

if __name__== '__main__':

    main()